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M. Broxvall

Örebro University, Applied Autonomous Sensor Systems, Alumnus

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University of Ulster

Alessandro Saffiotti

Örebro University

Consiglio Nazionale delle Ricerche (CNR)

University of Essex

Royal Holloway, University of London

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Papers by M. Broxvall

Robotic Ubiquitous Cognitive Ecology for Smart Homes

Journal of Intelligent & Robotic Systems, 2015

Robotic ecologies are networks of heterogeneous robotic devices pervasively embedded in everyday ... more Robotic ecologies are networks of heterogeneous robotic devices pervasively embedded in everyday environments, where they cooperate to perform complex tasks. While their potential makes them increasingly popular, one fundamental problem is how to make them both autonomous and adaptive, so as to reduce the amount of preparation, pre-programming and human supervision that they require in real world applications. The project RUBICON develops learning solutions which yield cheaper, adaptive and efficient coordination of robotic ecologies. The approach we pursue builds upon a unique combination of methods from cognitive robotics, machine learning, planning and agentbased control, and wireless sensor networks. This paper illustrates the innovations advanced by RUBICON in each of these fronts before describing how the resulting techniques have been integrated and applied to a smart home scenario. The resulting system is able to provide useful services and pro-actively assist the users in their activities. RUBICON learns through an incremental and progressive approach driven by the feedback received from its own activities and from the user, while also self-organizing the manner in which it uses available sensors, actuators and other functional components in the process. This paper summarises some of the lessons learned by adopting such an approach and outlines promising directions for future work.

Affordances in an ecology of physically embedded intelligent systems

The concept of Ecology of Physically Embedded Intelligent Systems, or Peis-Ecology, combines insi... more The concept of Ecology of Physically Embedded Intelligent Systems, or Peis-Ecology, combines insights from the fields of autonomous robotics and ambient intelligence to provide a new solution to building intelligent robotic systems in the service of people. The concept of Peis-Ecology also offers an interesting setting to study the applicability of Gibson's notion of affordances to an ecology of robots. In this paper we introduce this concept, and discuss its potential and implications both from an application point of view and from an ecological (Gibsonian) point of view. We also discuss some new scientific challenges introduced by a Peis-Ecology, present our current steps toward its realization, and point at a few experimental results that show the viability of this concept.

An Autonomous Spherical Robot for Security Tasks

2006 IEEE International Conference on Computational Intelligence for Homeland Security and Personal Safety, 2006

PEIS Ecology: integrating robots into smart environments

Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006., 2006

We introduce the concept of Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology. ... more We introduce the concept of Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology. This is a network of heterogeneous robotic devices (PEIS) pervasively embedded in the environment. A PEIS can be as simple as a toaster and as complex as a humanoid robot. PEIS can exchange information at different levels of abstraction, and share both physical and virtual functionalities to perform complex tasks. By putting together insights from the fields of autonomous robotics and of ambient intelligence, the PEIS-Ecology approach explores a new road to building assistive, personal, and service robots. In this paper, we discuss this concept, describe a first realization of it, and show an implemented use-case scenario.

Seamless integration of robots and tiny embedded devices in a PEIS-Ecology

2007 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2007

The fields of autonomous robotics and ambient intelligence are converging toward the vision of sm... more The fields of autonomous robotics and ambient intelligence are converging toward the vision of smart robotic environments, in which tasks are performed via the cooperation of many networked robotic devices. To enable this vision, we need a common communication and cooperation model that can be shared between robotic devices at different scales, ranging from standard mobile robots to tiny embedded devices. Unfortunately, today's robot middlewares are too heavy to run on tiny devices, and middlewares for embedded devices are too simple to support the cooperation models needed by an autonomous smart environment. In this paper, we propose a middleware model which allows the seamless integration of standard robots and simple off-the-shelf embedded devices. Our middleware is suitable for building truly ubiquitous robotics applications, in which devices of very different scales and capabilities can cooperate in a uniform way. We discuss the principles and implementation of our middleware, and show an experiment in which a mobile robot, a commercial mote, and a custom-built mote cooperate in a home service scenario.

Putting olfaction into action: using an electronic nose on a multi-sensing mobile robot

2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), 2004

Olfaction is a challenging new sensing modality for intelligent systems. With the emergence of el... more Olfaction is a challenging new sensing modality for intelligent systems. With the emergence of electronic noses it is now possible to detect and recognise a range of different odours for a variety of applications. An existing application is to use electronic olfaction on mobile robots for the purpose of odour based navigation. In this work, we introduce a new application where electronic olfaction is used in cooperation with other types of sensors on a mobile robot in order to acquire the odour property of objects. The mobility of the robot facilitates the execution of specific perceptual actions, such as moving closer to objects to acquire odour properties. Additional sensing modalities provides the spatial detection of objects and electronic olfaction then acquires the odour property which can be used for discrimination and recognition of the object being considered. We examine the problem of deciding when, how and where the e-nose should be activated by planning for active perception. We investigate the use of symbolic reasoning techniques in this context and consider the problem of integrating the information provided by the e-nose with both prior information and information from other sensors (e.g., vision). Finally, experiments are performed on a mobile robot equipped with an e-nose together with a variety of sensors that can perform decision making tasks in realistic environments.

Virtual 360° Panorama for Remote Inspection

2007 IEEE International Workshop on Safety, Security and Rescue Robotics, 2007

The use of remotely operated robotic systems in security related applications is becoming increas... more The use of remotely operated robotic systems in security related applications is becoming increasingly popular. However, the direct teleoperation interfaces commonly used today put a large amount of cognitive burden on the operators, thus seriously reducing the efficiency and reliability of these systems. In the context of an adjustable autonomy control architecture meant to relieve operators from unnecessary low-level tasks, we present an user interface technique for 360 • virtual panorama video as a perception aid to increase the situation awareness in tele-operation tasks, and as a block in the overall adjustable autonomy control architecture. At the hardware level, we rely on the intrinsic autonomy and robustness provided by the spherical morphology of our GroundBot robot. The work presented here is a step towards the overall goal of increasing the effectiveness of the GroundBot robot for remote inspection tasks.

A Navigation System for Automated Loaders in Underground Mines

Springer Tracts in Advanced Robotics, 2006

For underground mining operations human operated LHD vehicles are typically used for transporting... more For underground mining operations human operated LHD vehicles are typically used for transporting ore. Because of security issues and of the cost of human operators, alternative solutions such as tele-operated vehicles are often in use. Tele-operation, however, leads to reduced efficiency, and it is not an ideal solution. Full automation of the LHD vehicles is a challenging task, which is expected to result in increased operational efficiency, cost efficiency, and safety. In this paper, we present our approach to a fully automated solution currently under development. We use a fuzzy behavior-based approach for navigation, and develop a cheap and robust localization technique based on the deployment of inexpensive passive radio frequency identification (RFID) tags at key points in the mine.

Flexible infrastructure free navigation for vehicles in underground mines

2008 4th International IEEE Conference Intelligent Systems, 2008

During the last decade, mining companies and mobile equipment manufacturers have pursued improved... more During the last decade, mining companies and mobile equipment manufacturers have pursued improved efficiency, productivity, and safety in underground mining operations by automating some of the functions of underground vehicles. The work presented in this paper is the result of an effort to develop new flexible infrastructureless guidance system for autonomous tramming of center-articulated underground mining vehicles.

The PEIS-Ecology Project: Vision and Results

2008 Ieee/rsj International Conference on Robots and Intelligent Systems, Vols 1-3, Conference Proceedings, 2008

The vision of an Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology, combines in... more The vision of an Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology, combines insights from the fields of autonomous robotics and ambient intelligence to provide a new approach to building robotic systems in the service of people. In this paper, we present this vision, and we report the results of a four-year collaborative research project between Sweden and Korea aimed at the concrete realization of this vision. We focus in particular on three results: a robotic middleware able to cope with highly heterogeneous systems; a technique for autonomous self-configuration and reconfiguration; and a study of the problem of sharing information of both physical and digital nature.

Laser Based Intersection Detection for Reactive Navigation in an Underground Mine

2008 Ieee/rsj International Conference on Robots and Intelligent Systems, Vols 1-3, Conference Proceedings, 2008

In this paper we propose a new feature detection algorithm to enable junction recognition intende... more In this paper we propose a new feature detection algorithm to enable junction recognition intended for high speed reactive navigation in tunnel like environments. We also present an extensive experimental evaluation of the algorithm based on data recorded in a real mine. The algorithm is faster and has less environmental constraints than similar algorithms that can be found in the litterature.

Digital Representation of Everyday Objects in a Robot Ecology via Proxies

2008 Ieee/rsj International Conference on Robots and Intelligent Systems, Vols 1-3, Conference Proceedings, 2008

Robotic middlewares increasingly allow the seamless integration of multiple heterogeneous robots ... more Robotic middlewares increasingly allow the seamless integration of multiple heterogeneous robots into one distributed system. Unfortunately, very simple devices like tagged everyday objects and smart objects are left orphan in this otherwise pervasive trend. We claim that the inclusion of simple everyday objects as part of distributed robot systems would have many advantages, and propose a design pattern to allow this inclusion. We make this pattern concrete by describing an implementation of it using a specific multi-robot middleware, called PEIS-Ecology Middleware. We also show an illustrative experiment which integrates everyday objects in a smart home equipped with mobile robots as well as more advanced distributed sensor nodes.

An Evaluation of Local Autonomy Applied to Teleoperated Vehicles in Underground Mines

2010 Ieee International Conference on Robotics and Automation (Icra), 2010

Abstract Autonomous vehicles are being increasingly introduced in the mining industry. While thes... more

A middleware to integrate robots, simple devices and everyday objects into an ambient ecology

Pervasive and Mobile Computing, 2012

The fields of ambient intelligence, distributed robotics and wireless sensor networks are converg... more The fields of ambient intelligence, distributed robotics and wireless sensor networks are converging toward a common vision, in which ubiquitous sensing and acting devices cooperate to provide useful services in the home. These devices can range from sophisticated mobile robots to simple sensor nodes and even simpler tagged everyday objects. In this vision, a milkbox left on the table after the user has left the home could ask the service of a mobile robot to be placed back in the refrigerator. A missing ingredient to realize this vision is a mechanism that enables the communication and interoperation among such highly heterogeneous entities. In this paper, we propose such a mechanism in the form of a middleware able to integrate robots, tiny devices and augmented everyday objects into one and the same system. The key moves to cope with heterogeneity are: the definition of a tiny, compatible version of the middleware, that can run on small devices; and the concept of object proxy, used to make everyday object accessible within the middleware. We describe the concepts and implementation of our middleware, and show a number of experiments that illustrate its performance.

Laser-based corridor detection for reactive navigation

Industrial Robot: An International Journal, 2008

For mobile robots operating in real-world environments, reactive navigation is a useful complemen... more For mobile robots operating in real-world environments, reactive navigation is a useful complement (or even replacement) to pure plan-based metric navigation. Reactive navigation is performed with respect to local perceived features, rather than a global metric reference frame, and can provide reduced installation costs, increased flexibility, and robustness to changes in the environment. To be effective, however, reactive navigation requires fast and reliable perception of the relevant features in the environment. Corridor-like structures are one of the most common features that are used for this purpose. In this paper, we propose a new method for corridor detection from laser data, based on the Hough transform, which is fast, reliable, and noise tolerant. We describe the algorithm, report an extensive experimental evaluation of its performance, and motivate the research with a real application involving the autonomous operation of a loader vehicle in an underground mine.

Fast GPU Based Adaptive Filtering of 4D Echocardiography

IEEE Transactions on Medical Imaging, 2000

Time resolved three-dimensional (3D) echocardiography generates four-dimensional (3D+time) data s... more Time resolved three-dimensional (3D) echocardiography generates four-dimensional (3D+time) data sets that bring new possibilities in clinical practice. Image quality of four-dimensional (4D) echocardiography is however regarded as poorer compared to conventional echocardiography where time-resolved 2D imaging is used. Advanced image processing filtering methods can be used to achieve image improvements but to the cost of heavy data processing. The recent development of graphics processing unit (GPUs) enables highly parallel general purpose computations, that considerably reduces the computational time of advanced image filtering methods. In this study multidimensional adaptive filtering of 4D echocardiography was performed using GPUs. Filtering was done using multiple kernels implemented in OpenCL (open computing language) working on multiple subsets of the data. Our results show a substantial speed increase of up to 74 times, resulting in a total filtering time less than 30 s on a common desktop. This implies that advanced adaptive image processing can be accomplished in conjunction with a clinical examination. Since the presented GPU processor method scales linearly with the number of processing elements, we expect it to continue scaling with the expected future increases in number of processing elements. This should be contrasted with the increases in data set sizes in the near future following the further improvements in ultrasound probes and measuring devices. It is concluded that GPUs facilitate the use of demanding adaptive image filtering techniques that in turn enhance 4D echocardiographic data sets. The presented general methodology of implementing parallelism using GPUs is also applicable for other medical modalities that generate multidimensional data.

Disjunctions, independence, refinements

Artificial Intelligence, 2002

An important question in constraint satisfaction is how to restrict the problem to ensure tractab... more An important question in constraint satisfaction is how to restrict the problem to ensure tractability (since the general problem is NP-hard). The use of disjunctions has proven to be a useful method for constructing tractable constraint classes from existing classes; the well-known`maxclosed' and`ORD-Horn' constraints are examples of tractable classes that can be constructed this way. Three su cient conditions (the guaranteed satisfaction property, 1-independence and 2-independence) that each ensure the tractability of constraints combined by disjunctions have been proposed in the literature. We show that these conditions are both necessary and su cient for tractability in three di erent natural classes of disjunctive constraints. This suggests that deciding this kind of property is a very important task when dealing with disjunctive constraints. We provide a simple, automatic method for checking the 1-independence property|this method is applicable whenever the consistency of the constraints under consideration can be decided by path-consistency. Our method builds on a connection between independence and re nements (which is a way of reducing one constraint satisfaction problem to another.)

Extending a Networked Robot System with Tiny Devices and Everyday Objects

ABSTRACT

Extending a Networked Robot Systems to include Tiny Devices and Everyday Objects

Local autonomy for tele-operated vehicles

Robotic Ubiquitous Cognitive Ecology for Smart Homes

Journal of Intelligent & Robotic Systems, 2015

Robotic ecologies are networks of heterogeneous robotic devices pervasively embedded in everyday ... more Robotic ecologies are networks of heterogeneous robotic devices pervasively embedded in everyday environments, where they cooperate to perform complex tasks. While their potential makes them increasingly popular, one fundamental problem is how to make them both autonomous and adaptive, so as to reduce the amount of preparation, pre-programming and human supervision that they require in real world applications. The project RUBICON develops learning solutions which yield cheaper, adaptive and efficient coordination of robotic ecologies. The approach we pursue builds upon a unique combination of methods from cognitive robotics, machine learning, planning and agentbased control, and wireless sensor networks. This paper illustrates the innovations advanced by RUBICON in each of these fronts before describing how the resulting techniques have been integrated and applied to a smart home scenario. The resulting system is able to provide useful services and pro-actively assist the users in their activities. RUBICON learns through an incremental and progressive approach driven by the feedback received from its own activities and from the user, while also self-organizing the manner in which it uses available sensors, actuators and other functional components in the process. This paper summarises some of the lessons learned by adopting such an approach and outlines promising directions for future work.

Affordances in an ecology of physically embedded intelligent systems

The concept of Ecology of Physically Embedded Intelligent Systems, or Peis-Ecology, combines insi... more The concept of Ecology of Physically Embedded Intelligent Systems, or Peis-Ecology, combines insights from the fields of autonomous robotics and ambient intelligence to provide a new solution to building intelligent robotic systems in the service of people. The concept of Peis-Ecology also offers an interesting setting to study the applicability of Gibson's notion of affordances to an ecology of robots. In this paper we introduce this concept, and discuss its potential and implications both from an application point of view and from an ecological (Gibsonian) point of view. We also discuss some new scientific challenges introduced by a Peis-Ecology, present our current steps toward its realization, and point at a few experimental results that show the viability of this concept.

An Autonomous Spherical Robot for Security Tasks

2006 IEEE International Conference on Computational Intelligence for Homeland Security and Personal Safety, 2006

PEIS Ecology: integrating robots into smart environments

Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006., 2006

We introduce the concept of Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology. ... more We introduce the concept of Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology. This is a network of heterogeneous robotic devices (PEIS) pervasively embedded in the environment. A PEIS can be as simple as a toaster and as complex as a humanoid robot. PEIS can exchange information at different levels of abstraction, and share both physical and virtual functionalities to perform complex tasks. By putting together insights from the fields of autonomous robotics and of ambient intelligence, the PEIS-Ecology approach explores a new road to building assistive, personal, and service robots. In this paper, we discuss this concept, describe a first realization of it, and show an implemented use-case scenario.

Seamless integration of robots and tiny embedded devices in a PEIS-Ecology

2007 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2007

The fields of autonomous robotics and ambient intelligence are converging toward the vision of sm... more The fields of autonomous robotics and ambient intelligence are converging toward the vision of smart robotic environments, in which tasks are performed via the cooperation of many networked robotic devices. To enable this vision, we need a common communication and cooperation model that can be shared between robotic devices at different scales, ranging from standard mobile robots to tiny embedded devices. Unfortunately, today's robot middlewares are too heavy to run on tiny devices, and middlewares for embedded devices are too simple to support the cooperation models needed by an autonomous smart environment. In this paper, we propose a middleware model which allows the seamless integration of standard robots and simple off-the-shelf embedded devices. Our middleware is suitable for building truly ubiquitous robotics applications, in which devices of very different scales and capabilities can cooperate in a uniform way. We discuss the principles and implementation of our middleware, and show an experiment in which a mobile robot, a commercial mote, and a custom-built mote cooperate in a home service scenario.

Putting olfaction into action: using an electronic nose on a multi-sensing mobile robot

2004 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (IEEE Cat. No.04CH37566), 2004

Olfaction is a challenging new sensing modality for intelligent systems. With the emergence of el... more Olfaction is a challenging new sensing modality for intelligent systems. With the emergence of electronic noses it is now possible to detect and recognise a range of different odours for a variety of applications. An existing application is to use electronic olfaction on mobile robots for the purpose of odour based navigation. In this work, we introduce a new application where electronic olfaction is used in cooperation with other types of sensors on a mobile robot in order to acquire the odour property of objects. The mobility of the robot facilitates the execution of specific perceptual actions, such as moving closer to objects to acquire odour properties. Additional sensing modalities provides the spatial detection of objects and electronic olfaction then acquires the odour property which can be used for discrimination and recognition of the object being considered. We examine the problem of deciding when, how and where the e-nose should be activated by planning for active perception. We investigate the use of symbolic reasoning techniques in this context and consider the problem of integrating the information provided by the e-nose with both prior information and information from other sensors (e.g., vision). Finally, experiments are performed on a mobile robot equipped with an e-nose together with a variety of sensors that can perform decision making tasks in realistic environments.

Virtual 360° Panorama for Remote Inspection

2007 IEEE International Workshop on Safety, Security and Rescue Robotics, 2007

The use of remotely operated robotic systems in security related applications is becoming increas... more The use of remotely operated robotic systems in security related applications is becoming increasingly popular. However, the direct teleoperation interfaces commonly used today put a large amount of cognitive burden on the operators, thus seriously reducing the efficiency and reliability of these systems. In the context of an adjustable autonomy control architecture meant to relieve operators from unnecessary low-level tasks, we present an user interface technique for 360 • virtual panorama video as a perception aid to increase the situation awareness in tele-operation tasks, and as a block in the overall adjustable autonomy control architecture. At the hardware level, we rely on the intrinsic autonomy and robustness provided by the spherical morphology of our GroundBot robot. The work presented here is a step towards the overall goal of increasing the effectiveness of the GroundBot robot for remote inspection tasks.

A Navigation System for Automated Loaders in Underground Mines

Springer Tracts in Advanced Robotics, 2006

For underground mining operations human operated LHD vehicles are typically used for transporting... more For underground mining operations human operated LHD vehicles are typically used for transporting ore. Because of security issues and of the cost of human operators, alternative solutions such as tele-operated vehicles are often in use. Tele-operation, however, leads to reduced efficiency, and it is not an ideal solution. Full automation of the LHD vehicles is a challenging task, which is expected to result in increased operational efficiency, cost efficiency, and safety. In this paper, we present our approach to a fully automated solution currently under development. We use a fuzzy behavior-based approach for navigation, and develop a cheap and robust localization technique based on the deployment of inexpensive passive radio frequency identification (RFID) tags at key points in the mine.

Flexible infrastructure free navigation for vehicles in underground mines

2008 4th International IEEE Conference Intelligent Systems, 2008

During the last decade, mining companies and mobile equipment manufacturers have pursued improved... more During the last decade, mining companies and mobile equipment manufacturers have pursued improved efficiency, productivity, and safety in underground mining operations by automating some of the functions of underground vehicles. The work presented in this paper is the result of an effort to develop new flexible infrastructureless guidance system for autonomous tramming of center-articulated underground mining vehicles.

The PEIS-Ecology Project: Vision and Results

2008 Ieee/rsj International Conference on Robots and Intelligent Systems, Vols 1-3, Conference Proceedings, 2008

The vision of an Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology, combines in... more The vision of an Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology, combines insights from the fields of autonomous robotics and ambient intelligence to provide a new approach to building robotic systems in the service of people. In this paper, we present this vision, and we report the results of a four-year collaborative research project between Sweden and Korea aimed at the concrete realization of this vision. We focus in particular on three results: a robotic middleware able to cope with highly heterogeneous systems; a technique for autonomous self-configuration and reconfiguration; and a study of the problem of sharing information of both physical and digital nature.

Laser Based Intersection Detection for Reactive Navigation in an Underground Mine

2008 Ieee/rsj International Conference on Robots and Intelligent Systems, Vols 1-3, Conference Proceedings, 2008

In this paper we propose a new feature detection algorithm to enable junction recognition intende... more In this paper we propose a new feature detection algorithm to enable junction recognition intended for high speed reactive navigation in tunnel like environments. We also present an extensive experimental evaluation of the algorithm based on data recorded in a real mine. The algorithm is faster and has less environmental constraints than similar algorithms that can be found in the litterature.

Digital Representation of Everyday Objects in a Robot Ecology via Proxies

2008 Ieee/rsj International Conference on Robots and Intelligent Systems, Vols 1-3, Conference Proceedings, 2008

Robotic middlewares increasingly allow the seamless integration of multiple heterogeneous robots ... more Robotic middlewares increasingly allow the seamless integration of multiple heterogeneous robots into one distributed system. Unfortunately, very simple devices like tagged everyday objects and smart objects are left orphan in this otherwise pervasive trend. We claim that the inclusion of simple everyday objects as part of distributed robot systems would have many advantages, and propose a design pattern to allow this inclusion. We make this pattern concrete by describing an implementation of it using a specific multi-robot middleware, called PEIS-Ecology Middleware. We also show an illustrative experiment which integrates everyday objects in a smart home equipped with mobile robots as well as more advanced distributed sensor nodes.

An Evaluation of Local Autonomy Applied to Teleoperated Vehicles in Underground Mines

2010 Ieee International Conference on Robotics and Automation (Icra), 2010

Abstract Autonomous vehicles are being increasingly introduced in the mining industry. While thes... more

A middleware to integrate robots, simple devices and everyday objects into an ambient ecology

Pervasive and Mobile Computing, 2012

The fields of ambient intelligence, distributed robotics and wireless sensor networks are converg... more The fields of ambient intelligence, distributed robotics and wireless sensor networks are converging toward a common vision, in which ubiquitous sensing and acting devices cooperate to provide useful services in the home. These devices can range from sophisticated mobile robots to simple sensor nodes and even simpler tagged everyday objects. In this vision, a milkbox left on the table after the user has left the home could ask the service of a mobile robot to be placed back in the refrigerator. A missing ingredient to realize this vision is a mechanism that enables the communication and interoperation among such highly heterogeneous entities. In this paper, we propose such a mechanism in the form of a middleware able to integrate robots, tiny devices and augmented everyday objects into one and the same system. The key moves to cope with heterogeneity are: the definition of a tiny, compatible version of the middleware, that can run on small devices; and the concept of object proxy, used to make everyday object accessible within the middleware. We describe the concepts and implementation of our middleware, and show a number of experiments that illustrate its performance.

Laser-based corridor detection for reactive navigation

Industrial Robot: An International Journal, 2008

For mobile robots operating in real-world environments, reactive navigation is a useful complemen... more For mobile robots operating in real-world environments, reactive navigation is a useful complement (or even replacement) to pure plan-based metric navigation. Reactive navigation is performed with respect to local perceived features, rather than a global metric reference frame, and can provide reduced installation costs, increased flexibility, and robustness to changes in the environment. To be effective, however, reactive navigation requires fast and reliable perception of the relevant features in the environment. Corridor-like structures are one of the most common features that are used for this purpose. In this paper, we propose a new method for corridor detection from laser data, based on the Hough transform, which is fast, reliable, and noise tolerant. We describe the algorithm, report an extensive experimental evaluation of its performance, and motivate the research with a real application involving the autonomous operation of a loader vehicle in an underground mine.

Fast GPU Based Adaptive Filtering of 4D Echocardiography

IEEE Transactions on Medical Imaging, 2000

Time resolved three-dimensional (3D) echocardiography generates four-dimensional (3D+time) data s... more Time resolved three-dimensional (3D) echocardiography generates four-dimensional (3D+time) data sets that bring new possibilities in clinical practice. Image quality of four-dimensional (4D) echocardiography is however regarded as poorer compared to conventional echocardiography where time-resolved 2D imaging is used. Advanced image processing filtering methods can be used to achieve image improvements but to the cost of heavy data processing. The recent development of graphics processing unit (GPUs) enables highly parallel general purpose computations, that considerably reduces the computational time of advanced image filtering methods. In this study multidimensional adaptive filtering of 4D echocardiography was performed using GPUs. Filtering was done using multiple kernels implemented in OpenCL (open computing language) working on multiple subsets of the data. Our results show a substantial speed increase of up to 74 times, resulting in a total filtering time less than 30 s on a common desktop. This implies that advanced adaptive image processing can be accomplished in conjunction with a clinical examination. Since the presented GPU processor method scales linearly with the number of processing elements, we expect it to continue scaling with the expected future increases in number of processing elements. This should be contrasted with the increases in data set sizes in the near future following the further improvements in ultrasound probes and measuring devices. It is concluded that GPUs facilitate the use of demanding adaptive image filtering techniques that in turn enhance 4D echocardiographic data sets. The presented general methodology of implementing parallelism using GPUs is also applicable for other medical modalities that generate multidimensional data.

Disjunctions, independence, refinements

Artificial Intelligence, 2002

An important question in constraint satisfaction is how to restrict the problem to ensure tractab... more An important question in constraint satisfaction is how to restrict the problem to ensure tractability (since the general problem is NP-hard). The use of disjunctions has proven to be a useful method for constructing tractable constraint classes from existing classes; the well-known`maxclosed' and`ORD-Horn' constraints are examples of tractable classes that can be constructed this way. Three su cient conditions (the guaranteed satisfaction property, 1-independence and 2-independence) that each ensure the tractability of constraints combined by disjunctions have been proposed in the literature. We show that these conditions are both necessary and su cient for tractability in three di erent natural classes of disjunctive constraints. This suggests that deciding this kind of property is a very important task when dealing with disjunctive constraints. We provide a simple, automatic method for checking the 1-independence property|this method is applicable whenever the consistency of the constraints under consideration can be decided by path-consistency. Our method builds on a connection between independence and re nements (which is a way of reducing one constraint satisfaction problem to another.)

Extending a Networked Robot System with Tiny Devices and Everyday Objects

ABSTRACT

Extending a Networked Robot Systems to include Tiny Devices and Everyday Objects

Local autonomy for tele-operated vehicles